From patchwork Tue Oct 27 17:29:12 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: James Morse X-Patchwork-Id: 7499451 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id E672A9F327 for ; Tue, 27 Oct 2015 17:32:40 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E27A3208CE for ; Tue, 27 Oct 2015 17:32:39 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 202B22069F for ; Tue, 27 Oct 2015 17:32:37 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Zr85Q-0007Ft-Pw; Tue, 27 Oct 2015 17:31:04 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Zr850-000730-A3 for linux-arm-kernel@lists.infradead.org; Tue, 27 Oct 2015 17:30:40 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6C41A4F2; Tue, 27 Oct 2015 10:30:14 -0700 (PDT) Received: from melchizedek.cambridge.arm.com (melchizedek.cambridge.arm.com [10.1.209.158]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0D3CA3F21A; Tue, 27 Oct 2015 10:30:18 -0700 (PDT) From: James Morse To: linux-arm-kernel@lists.infradead.org Subject: [PATCH v2 03/11] arm64: Convert hcalls to use HVC immediate value Date: Tue, 27 Oct 2015 17:29:12 +0000 Message-Id: <1445966960-31724-4-git-send-email-james.morse@arm.com> X-Mailer: git-send-email 2.1.4 In-Reply-To: <1445966960-31724-1-git-send-email-james.morse@arm.com> References: <1445966960-31724-1-git-send-email-james.morse@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20151027_103038_729397_630946D5 X-CRM114-Status: GOOD ( 13.56 ) X-Spam-Score: -6.9 (------) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , "Rafael J. Wysocki" , Lorenzo Pieralisi , linux-pm@vger.kernel.org, Geoff Levand , Catalin Marinas , Will Deacon , AKASHI Takahiro , James Morse , Pavel Machek , Sudeep Holla , Marc Zyngier , wangfei , Kevin Kang MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Geoff Levand The existing arm64 hcall implementations are limited in that they only allow for two distinct hcalls; with the x0 register either zero or not zero. Also, the API of the hyp-stub exception vector routines and the KVM exception vector routines differ; hyp-stub uses a non-zero value in x0 to implement __hyp_set_vectors, whereas KVM uses it to implement kvm_call_hyp. To allow for additional hcalls to be defined and to make the arm64 hcall API more consistent across exception vector routines, change the hcall implementations to use the 16 bit immediate value of the HVC instruction to specify the hcall type. Define three new preprocessor macros HVC_CALL_HYP, HVC_GET_VECTORS, and HVC_SET_VECTORS to be used as hcall type specifiers and convert the existing __hyp_get_vectors(), __hyp_set_vectors() and kvm_call_hyp() routines to use these new macros when executing an HVC call. Also, change the corresponding hyp-stub and KVM el1_sync exception vector routines to use these new macros. Signed-off-by: Geoff Levand Signed-off-by: James Morse --- arch/arm64/include/asm/virt.h | 27 +++++++++++++++++++++++++++ arch/arm64/kernel/hyp-stub.S | 32 +++++++++++++++++++++----------- arch/arm64/kvm/hyp.S | 16 +++++++++------- 3 files changed, 57 insertions(+), 18 deletions(-) diff --git a/arch/arm64/include/asm/virt.h b/arch/arm64/include/asm/virt.h index 7a5df5252dd7..eb10368c329e 100644 --- a/arch/arm64/include/asm/virt.h +++ b/arch/arm64/include/asm/virt.h @@ -18,6 +18,33 @@ #ifndef __ASM__VIRT_H #define __ASM__VIRT_H +/* + * The arm64 hcall implementation uses the ISS field of the ESR_EL2 register to + * specify the hcall type. The exception handlers are allowed to use registers + * x17 and x18 in their implementation. Any routine issuing an hcall must not + * expect these registers to be preserved. + */ + +/* + * HVC_CALL_HYP - Execute a hyp routine. + */ + +#define HVC_CALL_HYP 0 + +/* + * HVC_GET_VECTORS - Return the value of the vbar_el2 register. + */ + +#define HVC_GET_VECTORS 1 + +/* + * HVC_SET_VECTORS - Set the value of the vbar_el2 register. + * + * @x0: Physical address of the new vector table. + */ + +#define HVC_SET_VECTORS 2 + #define BOOT_CPU_MODE_EL1 (0xe11) #define BOOT_CPU_MODE_EL2 (0xe12) diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index a272f335c289..017ab519aaf1 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -22,6 +22,7 @@ #include #include +#include #include #include @@ -53,14 +54,22 @@ ENDPROC(__hyp_stub_vectors) .align 11 el1_sync: - mrs x1, esr_el2 - lsr x1, x1, #26 - cmp x1, #0x16 + mrs x18, esr_el2 + lsr x17, x18, #ESR_ELx_EC_SHIFT + and x18, x18, #ESR_ELx_ISS_MASK + + cmp x17, #ESR_ELx_EC_HVC64 b.ne 2f // Not an HVC trap - cbz x0, 1f - msr vbar_el2, x0 // Set vbar_el2 + + cmp x18, #HVC_GET_VECTORS + b.ne 1f + mrs x0, vbar_el2 b 2f -1: mrs x0, vbar_el2 // Return vbar_el2 + +1: cmp x18, #HVC_SET_VECTORS + b.ne 2f + msr vbar_el2, x0 + 2: eret ENDPROC(el1_sync) @@ -100,11 +109,12 @@ ENDPROC(\label) * initialisation entry point. */ -ENTRY(__hyp_get_vectors) - mov x0, xzr - // fall through ENTRY(__hyp_set_vectors) - hvc #0 + hvc #HVC_SET_VECTORS ret -ENDPROC(__hyp_get_vectors) ENDPROC(__hyp_set_vectors) + +ENTRY(__hyp_get_vectors) + hvc #HVC_GET_VECTORS + ret +ENDPROC(__hyp_get_vectors) diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S index e5836138ec42..073b8bf3daf7 100644 --- a/arch/arm64/kvm/hyp.S +++ b/arch/arm64/kvm/hyp.S @@ -29,6 +29,7 @@ #include #include #include +#include #define CPU_GP_REG_OFFSET(x) (CPU_GP_REGS + x) #define CPU_XREG_OFFSET(x) CPU_GP_REG_OFFSET(CPU_USER_PT_REGS + 8*x) @@ -924,12 +925,9 @@ __hyp_panic_str: * in Hyp mode (see init_hyp_mode in arch/arm/kvm/arm.c). Return values are * passed in r0 and r1. * - * A function pointer with a value of 0 has a special meaning, and is - * used to implement __hyp_get_vectors in the same way as in - * arch/arm64/kernel/hyp_stub.S. */ ENTRY(kvm_call_hyp) - hvc #0 + hvc #HVC_CALL_HYP ret ENDPROC(kvm_call_hyp) @@ -960,6 +958,7 @@ el1_sync: // Guest trapped into EL2 mrs x1, esr_el2 lsr x2, x1, #ESR_ELx_EC_SHIFT + and x0, x1, #ESR_ELx_ISS_MASK cmp x2, #ESR_ELx_EC_HVC64 b.ne el1_trap @@ -968,15 +967,18 @@ el1_sync: // Guest trapped into EL2 cbnz x3, el1_trap // called HVC /* Here, we're pretty sure the host called HVC. */ + mov x18, x0 pop x2, x3 pop x0, x1 - /* Check for __hyp_get_vectors */ - cbnz x0, 1f + cmp x18, #HVC_GET_VECTORS + b.ne 1f mrs x0, vbar_el2 b 2f -1: push lr, xzr +1: /* Default to HVC_CALL_HYP. */ + + push lr, xzr /* * Compute the function address in EL2, and shuffle the parameters.